为了提高LAMOST-HRS(Large Sky Area Multi-Object Fiber Spectroscopy Telescope-High Resolution Spectrograph)光谱分辨率以及光谱仪效率, 并建立一套可在仪器概念设计阶段分析杂散光的方法, 开展了在不进行BSDF测量的前提下, 对系统杂散光建模、分析的研究。首先根据粗糙度测量数据计算关键参数, 构建Harvey散射模型。接着通过显微镜观察光学面, 由MATLAB进行图像处理获取最大颗粒直径, 构建颗粒污染散射模型。然后导入光谱仪镀膜、光学元件、机械结构。对机械结构进行简化以提高分析效率。最后预估杂散光背景, 分析杂散光路径与组成。结果表明, LAMOST-HRS杂散光主要由光学面散射引起, 杂散辐射率为2.55%, 信噪比为16.01 dB, 达到设计指标要求。

In order to improve the spectral resolution and spectrograph efficiency of LAMOST-HRS(Large Sky Area Multi-Object Fiber Spectroscopy Telescope-High Resolution Spectrograph), and set up the methods to analyze stray light in the conceptual design stage, the modeling and analysis of stray light without measuring BSDF were studied. First, the Harvey scattering model was constructed by calculating the key parameters according to the roughness measurement data. Then the optical surface was observed by microscope, and the maximum partical diameter was obtained by MATLAB image processing, and the particle pollution scattering model was built. The the coatings, optical element and mechanical structure of the spectrograph were imported. The mechanical structure was simplified to improve the efficiency of the analysis. Finally, the background of the stray light was estimated, and the path and composition of the stray light were analyzed. The results show that the LAMOST-HRS stray light is mainly caused by the scattering of optical surface. The stray light accounts for 2.55% of the total illumination of the CCD surface, and the signal-to-noise ratio is 16.01 dB, which meets the design requirements.